ATK Engines are TRASH..!! I had one of their engines and the head gasket blew Before the warranty was even 1/4 expired. Left me beside the road. I contacted ATK they told me I had to get the head removed, take it to a machinist get them to say it was bad, remember all of this is costing me Money and Downtime to Try and satisfy ATK for warranty. ATK said they would repay for the work which they NEVER DID. ATK also then told me i had to ship them the head which I did. After calling them for weeks they said it was not their fault (again, not what the machinist said). I told ATK to send me the head back and they refused. I spent months needing this vehicle on the road, calling them over and Over... They SCREWED me big time. their warranty only exist on paper and it Not worth the paper it is written on. RUN FROM ATK...